The present invention relates to contoured intake ducts and fan housing assemblies for floor care machines, such as vacuums, extractors, steam cleaners, and the like.
Many contemporary floor care machines are equipped with vacuum motors or other suction-generating apparatus for drawing particulates, fluids, or other materials from a floor surface and propelling such materials into a storage receptacle. Such floor care machines include upright and canister vacuums, extractors, steam cleaners, carpet shampooers, and other similar devices.
FIG. 1 is a side elevational, partially-exploded view of a floor care machine 20 (e.g. an upright vacuum) in accordance with the prior art. As is well known, the floor care machine 20 includes a head assembly 40 that engages a floor surface 22, and a dirt receptacle 26 for receiving and storing particulates. An exhaust duct 28 extends upwardly from the head assembly 40 and has an exhaust outlet 29 that extends partially into the dirt receptacle 26. A handle support 30 extends upwardly from the exhaust duct 28, and a handle 32 is attached to an upper end of the handle support 30.
FIG. 2 is an exploded isometric view of the head assembly 40 of the floor care machine 20 of FIG. 1. The head assembly 40 includes a motor assembly 42 having a fan housing 50 and a drive shaft 44 coupled to a drive belt 46. A roller brush 48 is also coupled to the drive belt 46. The fan housing 50 includes an intake opening 52 and an exhaust opening 54. The head assembly 40 also includes a lower housing 56, and an upper housing 58 that engages with the lower housing 56 to cover and protect the internal components of the head assembly 40.
The upper and lower housing 58, 56 form a suction compartment 60 surrounding the roller brush 48, and an intake duct 62 extending between the suction compartment 60 and the intake opening 52 of the fan housing 50. The intake duct 62 has a generally rectangular cross-section from the suction compartment 60 to the fan housing 50, however, at the point where the intake duct 62 meets the intake opening 52 of the fan housing 50, the cross-sectional shape of the intake duct 62 abruptly changes from a relatively large rectangular cross-sectional shape to a relatively small circular exit aperture 63. At the bottom of the suction compartment 60, an intake aperture 64 is disposed through the lower housing 56 that leads into the suction compartment 60.
In use, an operator grips the handle 32 and actuates a control switch (not shown) to transmit power to the motor assembly 42. As will be understood by persons of ordinary skill in the art, the motor assembly 42 creates suction within the suction compartment 60, drawing a particulate-laden airstream from the floor surface 12 through the intake aperture 64. The motor assembly 42 propels the particulate-laden airstream through the intake duct 62 and into the fan housing 50.
The particulate-laden airstream is then driven through the fan housing 50 and the exhaust duct 28, and into the dirt receptacle 26, where the particulates may be filtered from the particulate-laden airstream and stored for later disposal. Floor care machines of the type shown in FIGS. 1 and 2 are disclosed, for example, in U.S. Pat. No. 5,584,095 issued to Redding et al, U.S. Pat. No. 5,367,741 issued to Hampton et al, U.S. Pat. No. 5,230,121 issued to Blackman, U.S. Pat. No. 5,222,276 issued to Glenn, and U.S. Pat. No. 5,774,930 issued to Sommer et al.
Although desirable results have been achieved using the floor care machine 20, some drawbacks exist. For example, although the noise generated by floor care machines is of low volume and well within established limits for the comfort and safety of the operator and other persons in the vicinity of the machine, it may be desirable to further reduce the noise generated from the floor care machine. For some applications, such as in hospitals, hotels, or residential applications, it may be desirable to operate floor care machines while people are sleeping nearby. For other applications, such as in schools, universities, or office buildings, it may be desirable to operate floor care machines while people are quietly concentrating or conversing. Therefore, there is an ever-present desire to further reduce the noise generated by floor care machines.
The present invention is directed to contoured intake ducts and fan housing assemblies for floor care machines. In one aspect, an intake apparatus for a floor care machine includes a contoured duct having a passage therethrough, the passage having a first cross-sectional area at a first open end of the passage and a second cross-sectional area at a second open end of the passage. The first open end of the passage is adapted to be fluidly connected to a suction compartment of the floor care machine, and the second open end of the passage is adapted to be fluidly connected to an opening of an airflow propulsion device. The passage has a cross-sectional area progression from the first open end to the second open end that smoothly varies between the first cross-sectional area and the second cross-sectional area. Because the intake passage has a smoothly varying area progression, turbulence within the intake passage may be reduced or inhibited, and noise generated by the airstream within the intake passage may be reduced.
In another aspect, the contoured duct may include a bellmouth substantially surrounding the first open end. The bellmouth may inhibit the separation of the airstream within the intake passage, and thus, noise generated by the airstream within the intake passage may be reduced.
In a further aspect, an airflow propulsion device for a floor care machine may include a motor having a drive shaft, a fan operatively coupled to the drive shaft, and a fan housing disposed about the fan and having a transition passage proximate the radially-outward ends of the vanes of the fan. The transition passage extends to an exhaust opening and being sized to receive the outwardly-driven airflow from the fan. In one aspect, the fan housing includes an internal cowling surface closely conforming to and closely spaced from the distal edges of the vanes of the fan. In another aspect, the transition passage also has a cross-sectional area progression that smoothly varies between a first cross-sectional area proximate one of the vanes and a second cross-sectional area proximate the exhaust opening. Turbulence within the fan housing may be reduced or inhibited, and noise generated by the airstream within the fan housing may be reduced.